In most coolers, there is a requirement for a fan shaft to be horizontal. In the past, pump shafts have usually been vertical, and the pumps located within base tanks (see for example, U.S. Pat. No. 4,338,264). However there is a considerable saving to be effected if the pump shaft is coaxial with an horizontal fan shaft, but to achieve this, the pump must be below the water spreader but above the water level of the base tank.
One of the problems which is encountered with water distribution systems used heretofore is that, in the event of a tank running dry, unless a pump is of the small clearance (and sometimes unsatisfactory) self-priming type, it needs repriming. However, the pump is preferably of the large clearance centrifugal type, and if not reprimed will form an annulus of water within the housing and a central core of air, and this will prevent operation. Repriming as previously known is tedious and is an undesirable operation, particularly as sometimes it needs to be undertaken by people who are not mechanically skilled.
The main object of this invention is to provide improvements whereby a pump will be reprimed with water when not in use, so that once it is primed it is likely to remain primed, thereby enabling the pump to be coaxial with the fan (or blower) shaft.